Impeller of a suction-enforced type and fan-motor having the same

ABSTRACT

Disclosed are an impeller of a suction-enforced type, and a fan-motor for a vacuum cleaner having the same. The fan-motor having the impeller of the suction-enforced type includes: a motor housing; a motor installed in the motor housing; an impeller casing coupled to the upper portion of the motor housing; the impeller of the suction-enforced type installed in the impeller casing and connected to a rotation shaft of the motor; and a guide vane installed at the lower portion of the impeller of the suction-enforced type, for guiding the air sucked into the impeller casing to the motor side. As a result, suction efficiency of the impeller is improved, and thus efficiency of the fan-motor for the vacuum cleaner is improved.

TECHNICAL FIELD

The present invention relates to a fan-motor for a vacuum cleaner, andmore particularly, to an impeller of a suction-enforced type which isreduced in size and improved in suction force, and a fan-motor for avacuum cleaner having the same.

BACKGROUND ART

FIG. 1 is a vertical-sectional view illustrating a conventionalfan-motor for a vacuum cleaner. Referring to FIG. 1, in the conventionalfan-motor for the vacuum cleaner, a motor 4 composed of a stator 2 and arotor 3 is installed in a motor housing 1 having its upper portionopened, and a rotation shaft 5 is fit-pressed into the center portion ofthe rotor 3 in the up/down direction, and rotated with the rotor 3, fortransmitting power.

An opening unit of an impeller casing 6 having a suction hole 6 a on itstop surface is coupled to the upper opening unit of the motor housing 1.An impeller 7 coupled to the top end of the rotation shaft 5 for suckingthe air through the suction hole 6 a is installed inside the impellercasing 6. A guide vane 8 for guiding the air sucked into the impellercasing 6 by the impeller 7 to the motor side 4 is installed at the lowerportion of the impeller 7.

The guide vane 8 includes a body unit 9 formed in a circular planarshape with a predetermined thickness and area, a plurality of diffuservanes 10 installed on the edges of the top surface of the body unit 9 atregular intervals, for raising a pressure of the air passing through theimpeller 7, and a plurality of return vanes 11 installed on the bottomsurface of the body unit 9, for guiding the air pressure-raised by thediffuser vanes 10 to the motor side 4.

In the conventional fan-motor for the vacuum cleaner, when power isapplied to the motor 4, rotation force is generated in the rotor 3, forrotating the rotor 3. The rotation shaft 5 is rotated with the rotor 3.

When the rotation shaft 5 is rotated, the impeller 7 coupled to the topend of the rotation shaft 5 is rotated, to generate suction force. Bythe suction force, the air is sucked into the impeller casing 6 throughthe suction hole 6 a of the impeller casing 6. The sucked air passesthrough the impeller 7, and is discharged to the lateral direction ofthe impeller 7.

The pressure of the air passing through the impeller 7 is raised by thediffuser vanes 10 of the guide vane 8. The air having the raisedpressure is supplied to the lower side return vanes 11 through spaceunits 12 between the inner circumference of the impeller casing 6 andthe outer circumference of the guide vane 8, guided to the centerportion by the return vanes 11, and sent to the motor side 4.Accordingly, the motor 4 is cooled and the air is discharged.

The impeller 7 and the flow of the sucked air passing through theimpeller 7 will now be explained with reference to FIGS. 2 and 3.

FIG. 2 is a perspective view illustrating a general 2-dimensional (2D)impeller, and FIG. 3 is a partial cross-sectional view provided toexplain a flow passing through the impeller of FIG. 2.

As illustrated in FIG. 2, the impeller 7 includes a top plate 7 a havinga suction hole 7 a′ at its center portion to communicate with animpeller casing 6 to suck the air, a bottom plate 7 b being disposed tooverlap with the top plate 7 a, and having a shaft hole 7 b′ at itscenter portion so that a rotation shaft 5 can be inserted into the shafthole 7 b′, and a plurality of blades 7 c disposed between the top plate7 a and the bottom plate 7 b, isolated from each other in thecircumferential direction at regular intervals, and extended in theradial direction. Since the impeller 7 induces a 2D flow, it is calledthe 2D impeller.

As shown in FIG. 3, in a fan-motor for a vacuum cleaner using the 2Dimpeller 7, the air flow sucked into the suction hole 7 a′ of the topplate 7 a through a suction hole 6 a (refer to FIG. 1) of the impellercasing 6 is not smoothly transferred to the blade sides 7 c due to weakinduction in the suction hole 7 a′. That is, a suction flow loss occursin the suction hole side 7 a′.

In general, if a fluid flow undergoes a direction change or a suddenshape change, a flow loss is caused by a change degree. In the case ofthe 2D impeller 7, the sucked flow is bent at an angle of almost 90° andsent to gaps between the blades 7 c (refer to arrows).

A 3D impeller generally known to be suitable for high speed rotation(over 70,000 rpm) can be used to overcome the flow loss by inducing a 3Dflow. It will be explained below with reference to FIG. 4.

FIG. 4 is a perspective view illustrating a general 3D impeller, andFIG. 5 is a partial cross-sectional view provided to explain a flowpassing through the impeller of FIG. 4.

As depicted in FIG. 4, the 3D impeller 7′ includes a main body 7′ahaving a shaft hole 7′c into which a rotation shaft 5 is coupled, and aplurality of blades 7′b arranged along the outer circumference of themain body 7′a having predetermined curvature, and isolated from eachother with their upper portions bent.

As shown in FIG. 5, in the 3D impeller 7′ applied to a fan-motor for avacuum cleaner, the inducer unit formed by bending the upper portions ofthe blades 7′b straightens a sucked fluid and pushes the fluid to atarget direction, namely, to diffuser vane sides 10 disposed to surroundthe impeller 7′. This configuration reduces a flow loss in a suctionhole side 6′a of an impeller casing 6′ and facilitates a flow to thediffuser vane sides 10.

However, as illustrated in the above drawings, the 3D impeller 7′ ishigher than the 2D impeller 7, thereby increasing the size of theimpeller casing 6′. As a result, the size of the fan-motor for thevacuum cleaner increases, and the whole size of the vacuum cleanerincreases.

DISCLOSURE OF THE INVENTION

Therefore, an object of the present invention is to provide an impellerof a suction-enforced type which is reduced in size and improved insuction force.

Another object of the present invention is to provide a fan-motor for avacuum cleaner having the impeller of the suction-enforced type.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described herein,there is provided an impeller of a suction-enforced type, including: a2D impeller; and a 3D impeller installed at the center portion of the 2Dimpeller.

There is also provided an impeller of a suction-enforced type,including: a top plate having a suction hole at its center portion; abottom plate being isolated from the lower portion of the top plate at apredetermined interval, and having a shaft hole at its center portion sothat a rotation shaft can be coupled into the shaft hole; a plurality ofblades for coupling the top plate to the bottom plate between the topplate and the bottom plate, the blades being arranged along thecircumferential direction at regular intervals and extended in theradial direction; and an inducer unit formed at the center portion ofthe bottom plate, for inducing a suction flow from the suction hole ofthe top plate to the blades.

Preferably, the inducer unit is a 3D impeller disposed in a spacelimited by the inside ends of the blades.

Preferably, the inducer unit is formed by bending the inside top ends ofthe blades to one direction.

In addition, there is provided a fan-motor having an impeller of asuction-enforced type, including: a motor housing; a motor installed inthe motor housing; an impeller casing coupled to the upper portion ofthe motor housing; the impeller of the suction-enforced type installedin the impeller casing and connected to a rotation shaft of the motor;and a guide vane installed at the lower portion of the impeller of thesuction-enforced type, for guiding the air sucked into the impellercasing to the motor side.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is a vertical-sectional view illustrating a conventionalfan-motor for a vacuum cleaner;

FIG. 2 is a perspective view illustrating a general 2D impeller;

FIG. 3 is a partial cross-sectional view provided to explain a flowpassing through the impeller of FIG. 2;

FIG. 4 is a perspective view illustrating a general 3D impeller;

FIG. 5 is a partial cross-sectional view provided to explain a flowpassing through the impeller of FIG. 4;

FIG. 6 is a perspective view illustrating an impeller of asuction-enforced type in accordance with one preferred embodiment of thepresent invention;

FIG. 7 is a partial cross-sectional view provided to explain a flowpassing through the impeller of FIG. 6 in a fan-motor using theimpeller;

FIG. 8 is a graph showing suction power of the fan-motors using theimpellers of FIGS. 2, 4 and 6; and

FIG. 9 is a perspective view illustrating an impeller of asuction-enforced type in accordance with another preferred embodiment ofthe present invention.

MODES FOR CARRYING OUT THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

Hereinafter, an impeller of a suction-enforced type and a fan-motorhaving the same according to the present invention will be explained inmore detail with reference to the attached drawings.

FIG. 6 is a perspective view illustrating an impeller of asuction-enforced type in accordance with one preferred embodiment of thepresent invention, and FIG. 7 is a partial cross-sectional view providedto explain a flow passing through the impeller of FIG. 6 in a fan-motorusing the impeller.

Referring to FIG. 6, the impeller 100 includes a top plate 110, a bottomplate 120, blades 130 and an inducer unit 140.

The top plate 110 has a suction hole 111 at its center portion. Theupper portion of the top plate 110 is bent so that the center portion ofthe top plate 110 can be higher than the outer portion thereof. When theimpeller 100 is rotated by driving a motor 4, the outdoor air is suckedthrough the suction hole 111 communicating with a suction hole 6 a of animpeller casing 6.

The bottom plate 120 is formed in a disk shape, and isolated from thelower portion of the top plate 110 at a predetermined interval. Thebottom plate 120 has a shaft hole 121 at its center portion so that arotation shaft 5 can be inserted into the shaft hole 121.

The plurality of blades 130 are arranged between the top plate 110 andthe bottom plate 120. The height of each blade 130 is reduced from thecenter portion of the impeller 100 to the outer portion thereof. Theblades 130 are closely coupled to the top plate 110 and the bottom plate120. The blades 130 disposed between the top plate 110 and the bottomplate 120 are isolated from each other in the circumferential directionat regular intervals, and extended in the radial direction.

The inducer unit 140 is disposed in a space limited by the inside endsof the blades 130. Here, the inducer unit 140 is a 3D impeller.

As explained above, the 3D impeller 140 used as the inducer unitincludes a main body 141, and blades 143 formed along the outercircumference of the main body 141 in the up/down direction. A shafthole 145 into which the rotation shaft 5 is inserted is formed at thecenter portion of the main body 141.

As illustrated in FIG. 7, when the impeller 100 having the aboveconfiguration is applied to a fan-motor for a vacuum cleaner, the airsucked through the suction hole 6 a of the impeller casing 6 is inducedto the blade sides 130 by the inducer unit 140 without being bent at anangle of 90°. Therefore, the air can smoothly flow toward the blades 130without a large flow loss. Since the inducer unit 140 is installed inthe space limited by the inside ends of the blades 130, the size of theimpeller 100 does not increase.

The operation effect of the fan-motor for the vacuum cleaner using theimpeller 100 will now be described in detail with reference to FIG. 8.

FIG. 8 is a graph showing suction power of the fan-motors using theimpellers of FIGS. 2, 4 and 6.

As shown in FIG. 8, the conventional 3D impeller 7′ (refer to FIG. 4)shows the highest suction power, and the conventional 2D impeller 7(refer to FIG. 2) shows the lowest suction power. As a flux Q increases,suction power differences increase. When the flux Q is about 1.5 m³/s,each suction power W has the maximum value and decreases before/afterthe maximum value.

On the other hand, the impeller 100 of the present invention has highersuction power than the 2D impeller, and slightly lower suction powerthan the 3D impeller.

Another example of forming the inducer unit will now be described withreference to FIG. 9. FIG. 9 is a perspective view illustrating animpeller of a suction-enforced type in accordance with another preferredembodiment of the present invention.

Referring to FIG. 9, the impeller 200 includes a top plate 210 having asuction hole 211, a bottom plate 220 having a shaft hole 221, aplurality of blades 230 arranged between the top plate 210 and thebottom plate 220, for inducing the radial air flow, and an inducer unit231.

The inducer unit 231 is formed by bending the inside top ends of theblades 230 to one direction.

In this configuration, the inducer unit 231 for reducing a flow lossbelow a predetermined level can be formed merely by bending the insidetop ends of the blades 230 without adding a special component as in theabove embodiment.

In accordance with the present invention, the fan-motor for the vacuumcleaner uses one of the impellers 100 and 200 of the suction-enforcedtype. The operation of the fan-motor for the vacuum cleaner using theimpeller 100 of the suction-enforced type including the 3D impeller asthe inducer unit will now be described.

As shown in FIGS. 6 and 7, when the impeller 100 is rotated by therotation shaft 5, the air is sucked to the center portion of theimpeller 100 through the impeller casing 6.

The 3D impeller is installed as the inducer unit 140 at the centerportion of the impeller 100, so that the sucked air can be smoothlyinduced to the blades 130 by the inducer unit 140 without being bent atan angle of 90°. As a result, the flow loss is reduced at the centerportion of the impeller 100, thereby improving suction efficiency of thefan-motor.

A female screw thread is formed on the inner circumference of the shafthole 145 of the inducer unit 140 of the impeller 100. In a state wherethe impeller 100 is disposed, the female screw thread is directlyfastened to a male screw thread of the rotation shaft 5. That is, theinducer unit 140 serves as a nut. Accordingly, when only the impeller100 is fastened to the rotation shaft 5, any nut is not needed.

As discussed earlier, in accordance with the present invention, in theimpeller of the suction-enforced type and the fan-motor for the vacuumcleaner having the same, the inducer unit for smoothly inducing thesuction flow to the gaps between the blades is disposed at the suctionhole side of the impeller generating the flow loss. As a result, suctionefficiency of the impeller is improved, and thus efficiency of thefan-motor for the vacuum cleaner is improved.

In addition, when the 3D impeller is used as the inducer unit, the 3Dimpeller itself serves as a nut. Therefore, the impeller can be fastenedto the rotation shaft without using a special nut. That is, the numberof the components is reduced.

As the present invention may be embodied in several forms withoutdeparting from the spirit or essential characteristics thereof, itshould also be understood that the above-described embodiments are notlimited by any of the details of the foregoing description, unlessotherwise specified, but rather should be construed broadly within itsspirit and scope as defined in the appended claims, and therefore allchanges and modifications that fall within the metes and bounds of theclaims, or equivalence of such metes and bounds are therefore intendedto be embraced by the appended claims.

1. An impeller of a suction-enforced type, comprising: a top platehaving a suction hole at its center portion; a bottom plate beingisolated from the lower portion of the top plate at a predeterminedinterval, and having a shaft hole at its center portion so that arotation shaft can be coupled into the shaft hole; a plurality of bladesfor coupling the top plate to the bottom plate between the top plate andthe bottom plate, the blades being arranged along the circumferentialdirection at regular intervals and extended in the radial direction; andan inducer unit formed at the center portion of the bottom plate, forinducing a suction flow from the suction hole of the top plate to theblades, wherein the inducer unit includes a vertical blade and a bentblade bent horizontally from the top of the vertical blade, wherein thevertical blade is an inner end portion of one of the plurality of bladesthat extends from the bottom plate towards the suction hole, and whereina radially inner end of the vertical blade is spaced apart from theshaft hole.
 2. A fan-motor for a vacuum cleaner, comprising: a motorhousing; a motor installed in the motor housing; an impeller casingcoupled to the upper portion of the motor housing; an impeller of asuction-enforced type installed in the impeller casing and connected toa rotation shaft of the motor; and a guide vane installed at the lowerportion of the impeller of the suction-enforced type, for guiding theair sucked into the impeller casing to the motor side, wherein theimpeller of the suction-enforced type includes: a top plate having asuction hole at its center portion; a bottom plate being isolated fromthe lower portion of the top plate at a predetermined interval, andhaving a shaft hole at its center portion so that the rotation shaft canbe coupled into the shaft hole; a plurality of blades for coupling thetop plate to the bottom plate between the top plate and the bottomplate, the blades being arranged along the circumferential direction atregular intervals and extended in the radial direction; and an inducerunit formed at the center portion of the bottom plate, for inducing asuction flow from the suction hole of the top plate to the blades,wherein the inducer unit includes a vertical blade and a bent blade benthorizontally from the top of the vertical blade, wherein the verticalblade is an inner end portion of one of the plurality of blades thatextends from the bottom plate towards the suction hole, and wherein aradially inner end of the vertical blade is spaced apart from the shafthole.